1. Field of the Invention
The invention herein relates to methods for the control and suppression of fires, particularly those in which the fire is spread over a substantial area.
2. Description of Prior Art
There are many different types of fires which are difficult or impossible to fight in the conventional manner, such as by using water sprays and streams. For instance, many types of fires such as brush fires occur in locations which are not readily convenient to water supplies or where the terrain is such that it is difficult to bring available water to bear on the fire. Similarly, when fires occur in confined locations or indoors, such as in a factory or warehouse, the use of water for fire suppression may be dangerous or inappropriate, either because it will cause the burning material to spread to nearby areas or the water itself may cause damage to surrounding equipment and products.
There are also types of fires where water is not a satisfactory fire suppressant, either because it reacts with the burning material or because it cannot effectively suppress the fire. For instance, oil well fires and fires in burning pools of oil and other petroleum products are not readily susceptible to suppression with water streams and water sprays.
Further, water and similar liquid fire suppressants cannot normally be used to form fire barriers in permanent positions. For instance, it is desirable (and often required) that in certain types of vehicles there be a permanent fire suppressing barrier between the engine compartment and the passenger compartment. This barrier is intended to control a fire which occurs in the engine compartment and either prevent it from passing through into the passenger compartment or at least to retard the fire for a sufficient period that the occupants of the passenger compartment can escape from the vehicle before the fire reaches the passenger compartment. Water and other liquids, even if in a suitable container formed in the shape of a barrier, will often fail at the critical moment, such as in a road accident in which the container is damaged so that the liquid runs out at exactly the time that a fire is starting in the engine compartment from the accident. Consequently, just when such a barrier is most needed, the liquid has escaped and the barrier is rendered useless.
Over the years there have been a wide variety of solid materials which have been used for fire suppressance. As an example, in U.S. Pat. No. 4,665,993 is described the use of water-containing cellulosic fiber mats made from materials such as corn cobs, corn stalks, straw, cane, dry leaves and cardboard. These mats are saturated with water in a water: fiber ratio range of 1-50;1, based on weight of water per unit weight of the cellulosic material. Thus the devices of this patent are in effect merely an alternative way of delivering quantities of water to the fire site and of course require that there be a convenient source of water present to saturate the cellulosic mats before they are applied to the fire.
We have previously described use of dealginated, partially dewatered kelp waste for the purpose of absorption of oil and other waste liquids in our U.S. Pat. No. 5,009,790.
It would be very desirable for fire fighters to have available a convenient, low cost, effective, environmentally safe material which could be used for the suppression, control or extinguishing of fires under a wide variety of conditions or in areas where ordinary suppression means such as water streams and sprays are either ineffective, unavailable or dangerous to use.